Can't drill a straight hole?

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'owdy,
Back in the 80's I picked up a Craftsman 13" floor-standing drill press. Seemed like a decent unit given the modest price.
I've got a little project with curly maple, and find I can't drill a straight hole to save my soul.
With a long bit very carefully chucked and sitting by a reliable square, I eyeball the angle from the front and side. Appears to be as close to 90 degrees as I'm likely to get.
The maple is near 1" thick. I very carefully mark the center, then start a pilot hole with an ice pick and a drill bit. Then I try for the hole, going thru about 4" of wood. It comes out the other end, about 1/3 " from one side and 2/3" from the other.
I've tried several bits. Don't think I've ever seen an Irwin spade bit that didn't wobble. Picked up a Milwaukee extra-length 1/4" bit at HD and found it wobbled like crazy. But I doubt the bit is the real problem.
I'm guessing maybe the bit hits a hard spot in the wood, bends a little, and veers off course. But I'm no drill press pro. For all I know, there may be lots of other possibilities.
Hate to have to ask, but ... any tips on how to drill a straight hole? :-)
Thx, Will
"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."
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Sometimes pecking down the hole is the best way. Driving down jams wood as there is plenty to get rid of and it shifts it sideways.
Martin
On 3/1/2011 10:30 PM, Puddin' Man wrote:

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"Puddin' Man" wrote:

What is diameter and depth of hole?
Lew
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Puddin' Man wrote:

Using a twist drill bit? Don't.
Use a brad point or forstner...something that cuts with spurs on the outside rather than on the tip. An auger bit would work too but not (well) in a DP as the screw point will tend to pull the chuck right out of the DP.
--

dadiOH
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dadiOH wrote:

You may have a problem finding a brad point bit long enough. Ditto foerstner. NP, drill an inch, inch and a half so and then switch to your twist bit. The upper hole you drilled with the brad or foerstner bit will keep it from wobbling and or wandering so much.
If you don't *have* either, drill a series of 1/4" holes in scrap wood, cut them apart so you can stack them an inch or two high, slip a wood dowel through them, clamp to what you want to drill. remove dowel and drill away.
--

dadiOH
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Puddin' Man wrote,on my timestamp of 2/03/2011 3:30 PM:

Don't eyeball: get the square right up against the drill bit and see if it is really square in two 90degree directions.

Use a forstner (sp?) bit and do *not* drill a pilot hole. Forstner bits and other similar ones work best when the tip is used to guide the rest of the bit. With a pilot hole, you got nowhere for the tip to land on and the whole thing wobbles as the outer cutters pull in odd directions.
HTH
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snipped-for-privacy@yahoo.com.au says...

1/4 inch diameter and four inches deep is going to be a bear to drill with a Forstner. Deep holes are not what they do best.
Basic principle--for a given diameter bit the accuracy with which one can drill decreases with depth. In metalworking a ratio of 5:1 between bit diameter and hole depth is generally the limit for just putting the bit in and bearing down--beyond that you need to start applying deep hole drilling techniques. The particular hole is at a 16:1 ratio-- getting it clean and on center without a gun drill is going to be a pain in the butt.
First thing to consider--shorten the hole. How? Drill from both sides--that way you only need to deal with an 8:1 ratio. That's doable to typical woodworking tolerances if you're careful.
Next, use the right bit. Needs to be something that at least tries to self-clear--that can be a twist drill or brad point or auger. Don't even think about trying to do it with a spade bit or a Forstner. Lee Valley's brad points are really good. I'd avoid an auger just because the ones that are readily available are intended for rough carpentry in softwoods--they need some work before they have a real chance of making precise holes and won't be happy dealing with maple.
Next, you need some kind of jig to precisely position the bit. That doesn't have to be anything elaborate, just carefully made. A Harbor Freight dowelling jig for 13 bucks (remember to adjust the centering on it--out of the box it's not usually adjusted) and a plastic speed square should get you there for under 20 bucks, but you can cobble something up out of scraps without too much difficulty.
Now, with the jig in place, and with the piece absolutely square to the bit, drill about 3/4 of an inch, pull the bit out, clear the hole (when I say "clear the hole" I mean pull the bit out and either turn the piece upside down and whack it a couple of times or blow the hole with compressed air. Drill again to about 1-1/4, clear the hole. Drill to 1-5/8, clear the hole. Drill to 1-3/4, 1-7/8, 2, clearing each time. Now flip the piece and repeat. At the end drill all the way through.
You end up with a hole that's perfectly aligned on both ends, clear all the way through, no tearout on either side, and although it won't be perfectly straight it should be straight enough for most purposes.
If that doesn't get it straight enough and you can't afford a proper gun drill then you have to make the part as a composite--rip the piece, joint and plane, cut two half-rounds with a router, then glue it up and you end up with a very straight, very clean hole.
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So I've discovered.

I've been doing this.

I have a decent 1/4" brad point that will penetrate about 2.25" ...

Not certain I understand. Position the bit? Or position the workpiece?
I have a cheap drill press vise, and I've tried it on this project, but it's a bitch to use.

I've been clearing the hole but not necessarily at increments as small as you suggest.

I managed this I think once (out of about 8 differing attempts).
Someone commented on marking the center to start the hole. I've been laying out with a carpenters square from both sides. Then I start a tiny dimple with an ice-pick. Then enlarge the dimple manually with the actual bit that will be used for drilling thru. Same procedure, both top and bottom.

Not practical for the current project. Maybe for others.
Many Thanks, P
"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."
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Did you try to resharpen the bit with even tapers and sharpness on both sides?
Increase your peed a bit and do not "press" so hard to make the bit wander as much?
Once the pilot hole is drilled the next bit will basically always follow that one. The initial hole needs to start will a firm bit and not one that will bend as much.
Use a larger bit than needed for stiffness and collet each end?
----------------
"Puddin' Man" wrote in message
Someone commented on marking the center to start the hole. I've been laying out with a carpenters square from both sides. Then I start a tiny dimple with an ice-pick. Then enlarge the dimple manually with the actual bit that will be used for drilling thru. Same procedure, both top and bottom.

Not practical for the current project. Maybe for others.
Many Thanks, P
"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."
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You can get your table to *exactly* 90deg using this method:
Chuck a piece of wire or coat hanger into your DP bent in a Z shape. Adjust the wire so the tip barely touches the table at the edge. Rotate the chuck slowly by hand and watch the tip of the wire. Adjust the table as necessary so that the wire is just touching the table through a full rotation of the chuck.
You can shim the table as needed with bits of a cut up soda can if needed.
After the table is "dead on balls accurate" (It's an industry term) you can use the other methods described to drill a straight hole.
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This is worth trying, for starters.
It will be done before the week's out.
Thanks, P
wrote:

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."
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I agree on this method. It works simply and reliably.
On 3/2/2011 9:19 AM, Limp Arbor wrote:

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Puddin' Man wrote:

Drill from one side half way,then from the other side drill right through, the ends of the hole are where you want them, At the centre of the wood the hole may end up a bit oversize.
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Don't forget to clear the chips from the drill bit by occassionaly backing out the bit to allow the chips to dispurse. JoeG
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Just a couple of things that I'm surprised weren't mentioned:
First, use as short of a drill bit as possible -- the longer the drill bit, the more likely it will bend. If you have to do a deep hole, start with a short drill bit, and finish with a long one.
Next, mark the spot where you want to drill with a pencil -- not a centerpunch -- if you mark with a center punch, and you misalign the wood, the bit will pull itself off center right from the get-go, and you will end up with a slanted hole. Same deal with 'touch marking', where you lower the drill bit to make just a small mark to see if it's on center, and then you adjust the piece... don't do that!
Last, use a clamp to avoid the wood moving while you're drilling.
John
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Are you able to flip the piece and try it from the other side?
On 03/01/2011 11:30 PM, Puddin' Man wrote:

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"Puddin' Man" wrote in message

How are you securing the material being drilled to the drill press table? When I've had problems like that it was because the work piece was moving.
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Drill a pilot hole before using a cheap bit. Chuck in a steel rod instead of a drill bit to test for square -- bits are usually tapered a few thou to prevent binding, and a longer rod gives you a better reading than a short bit. Test the rod for straightness by rolling it.
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On 3/2/11 5:49 PM, Father Haskell wrote:

Um... excuse me? I'm calling BS on this. I'll gladly retract, but you have to cite something. :-)
--

-MIKE-

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